Cable insulation slitting tool



G. W. STALEY Dec. 5, 1944.

CABLE INSULATION SLITTING TOOL Filed Feb. 11, 1944 2 Sheets-Sheet 1 aw w. STALE) Dec. 5, 1944. G. w. STALEY CABLE INSULATION SI JITTING TOOL Filed Feb. 11, 1944 r 2 Sheets-Sheet 2 Patented Dec. 5, 1944 UNITED STATES PATENT OFFICE CABLE INSULATION SLITTING TOOL Guy W. Staley, Robbinsdale, Minn.

Application. February 11, 1944, Serial No. 521,990

6 Claims.

This invention relates to a cable insulation slitting tool and it is one object of the invention to provide a tool by the use of which the insulation of an electric wire or cable may be very easily slit longitudinally preparatory to removal of a portion of the insulation from the wire.

Another object of the invention is to so form the tool that it maybe used for slitting insulation at an end portion of a wire or at an intermediate portion thereof.

Another object of the invention is to provide a tool of this character including a trough-shaped body having a handle at one end and carrying a blade holder near its other end, the blade holder,

being slidable toward and away from the body so that the blade may be caused to penetrate the insulation of a wire and form a slit longitudinally thereof when pull is exerted upon the handle.

Another object of the invention is to provide the tool with a blade holder of such formation that a blade may be disposed radially of a wire to be stripped and adjusted so that it will cut through the insulation without cutting into the wire as the tool is-drawn along a cable.

Another object of the invention is to mount the blade holder upon rods or pins disposed at such an angle that as the tool is pulled along a cable the blade holder will be urged toward the cable and the blade thus caused to form a slit in the insulation longitudinally of the cable.

The invention is illustrated in the accompanying drawings, wherein:

Figure 1 is a side elevation showing the slitting tool applied to a cable.

Figure 2 is a top plan view thereof.

Figure 3 is a view showing the tool in end elevation and the cable in cross section.

Figure 4 is a sectional View taken longitudinally through the tool on the line 4-4 of Figure 3.

Figure 5-is a view on the line '5-5 of Figure 4.

Figure 6 is a transverse sectional view on the line 6-6 of Figure 4.

Figure 7 is a fragmentary view taken longitudinally through the tool and illustrating the manner in which the blade penetrates the insulation of a cable.

Figure 8 is a transverse sectional view on the line 3-8 of Figure 7.

This improved insulation slitting tool has a body I formed of stiff metal or other suitable material. The body is V-shaped in cross section to form a trough 2 and has a handle 3 at its front end so that by grasping the handle the tool can be drawn along a cable 4 and form a longitudinally extending slit in the insulation 5, the slit extending through the insulation to the wire 6'. After the insulation has been slit it can be easily removed from the wire and if a number of slits are formed in the insulation, strips of insulation will be formed which may then be cut across their attached ends and very easily removed, so that a portion of the wire of a desired length may be bared. Since the trough 2 is openfor the full length of the body, insulation may be slit at an end portion of a cable, or at an intermediate portion thereof when it is desired to connect a branch wire with a. main wire at a point spaced from ends of the main wire.

Rods or posts I extend upwardly from bosses 8 at one side of the body and while the posts have been shown integral with the bosses in Figures 6 and 8, it will be understood that they may be formed separate therefrom and screwed into the bosses if so desired. These posts and the bosses carrying them extend upwardly at a forward incline and upon the posts are slidably mounted sleeves 9 which are formed integral with one side of a bar I0 and also extend upwardly at a forward incline so that they are alined with the bosses 8 and may slide freely upon the posts. Rings I I or equivalent members are carried by the posts near their upper ends to limit movement of the sleeves off upper ends of the posts. The bar In is ,formed with a slot or opening I2 midway its length to slidably receive a blade I3 which is disposed vertically and has its upper portion gripped between clamping bars or jaws I4 and I5. These jaws are formed of metal and, at their outer ends, are formed with heads I4 and I5. Screws I6 pass through openings I! in the heads of the jaws and have their threaded lower end portions screwed into threaded openings I8 formed nearv ends of the bar I0, there being springs I9 about the screws to urge the jaws upwardly against the heads of the screws but allow the jaws to be shifted downwardly when the screws are turned in the proper direction. Screws 20, which pass transversely through the jaw I4 and are screwed into openings formed in the jaw I5, serve to draw the jaw into tight gripping engagement with the blade. By this arrangement, the blade may be vertically adjusted and then secured by tightening the screws 20 and, by adjusting the screws I6, the jaws may be supported at such height above the bar In that when the insulation is to be stripped from a cable; the blade will only project from the under face of the bar a sufficient distance to cut through the insulation but not cut into the wire. A general or approximate adjustment may thus be made by shifting the blade and tightening the screws 20 and a finer adjustment may then be made to accommodate the blade to insulation of a particular thickness.

When this wire stripper is in use, the body is applied to a cable as shown in Figure 1 of the drawings, with the cable resting in the trough 2 and the blade resting upon the insulation. The fact that the sleeves 9 are slidable along the posts permits the bar to shift downwardly along the posts until the blade rests upon the insulation.

Pressure is then applied to force the blade through the insulation and pull is exerted longi tudinally of the cable by grasping the handle 3. As the tool is drawn along the cable, the blade will form a slit in the insulation and since the posts are inclined as shown the sleeves 9 will have a tendency to move downwardly and thus retain the bar in contact with the cable and the blade in slitting engagement with the insulation. After a slit has been made in the insulation, the insulation may be immediately cut loose at its attached end and the wire laid bare, or a number of slits cut to form strips of insulation which are then out free to expose a bared length of wire.

Since the body is provided with posts I at only one side, the tool may be applied to the cable by shifting it transversely into place and, therefore, it may be applied near an end of the cable for stripping insulation from one end thereof, or

the tool may be applied to an intermediate portion of the cable and a portion spaced from ends of the insulation removed.

The fact that front end portions 2| of the side walls of the body are gradually reduced in depth, as shown in Figure 4, makes it easier to apply the tool and also disposes the handle 3 in such position that it may be conveniently grasped for drawing the tool along a cable.

Having thus described the invention, what is claimed is:

l. A cable insulation slitting tool comprising a body open along its upper portion to provide a cable-receiving trough having open front and rear ends, the body being adapted to be grasped at its front end and drawn along a cable, posts extending upwardly at a forward incline from a Side of the rear end portion of said body and spaced from each other longitudinally of the body, a bar over said body slidable along said posts toward and away from the body and formed with an opening, a clamp over said bar, a blade adjustably carried by said clamp and slidably passing through the opening of said bar, screws passing through said clamp and having threaded engagement with said bar, the screws mounting the clamp for movement toward and away from the bar. and springs about said screws yieldably resisting movement of the clamp toward the bar.

2. A cable insulation slitting tool comprising a body formed along its upper portion with a cablereceiving trough, a hand-hold at the front end of said body, a blade holder over said trough, and a blade carried by said holder for cutting a longitudlnally extending slit through insulation of a cable as the body is drawn along the cable, said blade holder being movable toward and away from the body, and the blade holder havingmovement toward the rear end of the body as it moves toward the body.

3. A cable insulation slitting tool comprising a body formed with a cable-receiving portion and adapted to be shifted longitudinally along a cable, a blade holder opposite the cable receiving portion mounted for movement toward and away from the body and longitudinally of the body, and a blade carried by the blade holder for penetrating insulation of a cable as the holder is moved toward the body and cutting a slit longitudinally of the insulation as the body is shifted along a cable.

4. A cable insulation slitting tool comprising a body formed with a cable-receiving trough and adapted to be shifted longitudinally along a cable, posts at one side of the trough spaced from each other longitudinally of the body and extending from the trough at an incline toward the front end of the body, a blade holder slidable along said posts toward and away from the trough and having movement longitudinally of the body toward the rear end thereof as it approaches the trough, and a blade carried by the blade holder for penetrating insulation and forming a slit longitudinally of a cable as the body is moved along the cable.

5. A cable insulation slitting tool comprising a body formed with a cable-receiving trough and adapted to be shifted longitudinally along a cable, posts at one side of the trough spaced from each other longitudinally of the body and extending from the trough at an incline toward the front end of the body, a bar opposite said trough having sleeves fitting about said posts and mounting the bar for movement along the posts toward the trough and longitudinally of the body, a clamp carried by said bar and shiftable toward and away from the bar, and a blade carried by said clamp and projecting therefrom toward the trough for penetrating insulation of a cable and forming a slit longitudinally thereof as the body is moved along the cable.

6. A cable insulation slitting tool comprising a body formed with a cable-receiving trough and adapted to be shifted longitudinally along a cable, posts at one side of the trough spaced from each other longitudinally of the body and extending from the trough at an incline toward the front endof the body, a bar opposite said trough hav-.

ing sleeves fitting about said posts and mounting the bar for movement along the posts toward the trough and longitudinally of the body, a clamp having companion jaws in side by side relation to each other and heads at their outer ends, screws passing through said jaws for drawing the jaws into gripping engagement with a blade disposed between the jaws, screws carried by said bar and passing through the heads of the jaws to slidably mount the clamp, and springs about said last mentioned screws between the bar and the heads of the jaws and yieldably resisting movement of the clamp toward the bar.

GUY W. STALEY. 

